The subject matter disclosed herein relates generally to multicavity sealing of opposing ports in spaced apart walls and, more particularly, for sealing the inspection access ports in gas turbine engines.
Gas turbine engines operate in a very high temperature and pressure environment. These engines typically have multiple casings with spaced apart walls having oppositely placed ports for inserting any type of inspection devices such as borescopes, proximity probes, or laser probes for inspection or intermittent access to the gas path components and for monitoring the engine. These inspection ports need to be plugged or sealed after the inspection is completed to prevent leakage through the ports when the engine is in operation. In the past, the sealing surfaces have been limited to one or two sealing surfaces with a maximum of three operating pressures, for example, exterior, intermediate and gas path operating pressures. However, in newer engines, the number of simultaneous sealing surfaces may include three or more sealing surface.
Further, gas turbine engines have different temperatures in different casings that lead to differential thermal growth of the casings, leading to misalignment in the oppositely placed ports in the spaced apart walls of the casings. Another factor contributing to the misalignment of holes is the radial, axial and circumferential movement of various surfaces with respect to each other due to pressure, mechanical loads, and temperature variations in the different chambers. Misalignment of the multiple ports in the spaced apart walls may lead to leakage if the ports are not properly sealed, which can result in lowering the overall efficiency of the engine, degrade or damage engine components, and potentially pose a safety hazard to personnel if hot gases leak to the exterior of the engine.